I used to be like your father-in-law, pride, vanity, stubborn, not wanting to be told what to do, whatever it was. And my dad was like this too (the hearing loss is heritable), I used to mock him about not wanting hearing aids before my own hearing declined. When I finally got fitted, it was shocking to me how much my hearing had suffered. Suddenly I could hear birds and crickets again, and most importantly speech!
Maybe you can get your father-in-law to first play around with AirPods as hearing aids to win him over to get proper ones. The latest generation hearing aids, like the AP's, have amazing AI signal processing that will suppress noise and enhance speech. It's always cool when my Phonak's detect noise and shut it down.
The important thing about hearing loss in elderly, especially if someone has an elevated risk of cognitive decline, is the resulting social isolation, and the increasing risk of dementia [1]. It should be addressed sooner than later.
To sum it up, the AP's have the potential to provide an affordable on-ramp for more hearing impaired people to experience hearing restoration and warm up to better ones (hopefully covered by insurance). I don't think AP's would a permanent hearing solution, other than for people who are uninsured and can't afford real hearing aids (sadly).
Edit: I could not imagine wearing AP's all day, great as they are, while I don't even notice my receiver-in-ear hearing aids anymore.
Edit: While AP's are not perfect, having any kind of hearing aid is a 100% improvement over having none, which is probably also why the FDA allowed OTC hearing aids.
Edit: [1] https://www.nih.gov/news-events/nih-research-matters/hearing...